[Grammar] why an apostrophe is needed in doctor's

[kwfine]

Dear teachers,

I don't understand why an apostrophe is needed in this sentence:
Tom went to the doctor's.
but
Tom went to see a doctor.


Could you explain please?

Thank you.

 

[Gillnetter]

Dear teachers,

I don't understand why an apostrophe is needed in this sentence:
Tom went to the doctor's. The way this is written is incorrect. Either, "Tom went to the doctor's office" or, "Tom went to the doctor". When you write "doctor's" you are indicating possession, something the doctor owns - "Tom went to the doctor's party - Tom went to the doctor's graduation - Tom went to the doctor's laboratory.
but
Tom went to see a doctor.


Could you explain please?

Thank you.

Gil

 

[Rover_KE]

"Tom went to the doctor's" is just fine in BE. We understand this to mean "...to the doctor's surgery" in the same that we say "...to the chemist's (shop)/butcher's (shop)."